I also work at a Chevy dealer and I am the master technology expert. There is a new bulletin that came out 10.27.17 that shares the new iPhone x is NOT compatible with any of our wireless charging systems. I have done exhausting research, trials, and questioned GM tech line. Not getting any really good answers on why not. Iphone 8,
samsung galaxy s6 active, S7 & S7 active work on the follwing 2018 models . Buick enclave,
Cadillac Esclade, Chevy bolt, Chevy Tahoe, Silverado (LD/HD), Suburban, GMC terrain,
yukon (short and xl), and the sierra LD/HD trucks. As of now, that's it. See pic attached to other compatible devices.
. If you look up #17-na-142 in the SI system there is more info. Document ID is 4779442
Have any questions reach out, just google Chevy Dude